These seamless helium-free 18″ balloons are the World’s Strongest Balloon! Specially engineered plastic polymers with metallic flake keep them looking shiny, brilliant, and fade-free for months to years! These are the only internally seamless air-filled permanent and reusable balloons on the market today. Whether you are in an arctic, tropical or extremely windy region, no balloon can stand up to the elements better than DuraBalloon®. Although they are made to last many months to years, we recommend replacing DuraBalloons® after about 6 Months due to average amounts dirt and grime build-up that may reduce their original bright shimmer. DuraBalloon® Products are round in shape and easily screwed into their fiberglass stem holders. Inflate via the Fast Flow inflator, an Inflator Tip with your bike pump, or any other compressor or automotive service center with a tapered inflation nozzle. Inflate by mouth or via our inflator/deflator sold separately. Many colors and styles to choose from.